Concentration and temperature profiles in a fixed bed column based on an analytical solution of the axial dispersion model for binary and multicomponent non-isothermal adsorption processes

Three solids flow models for gas flowing solids fixed bed contactors are analyzed. They all presume axial dispersion in the dynamic, freely flowing zone, but they differ in the interpretation of the stagnant zone. The models have been examined and the model parameters have been optimized on the basis of two types of tracer experiments. One provides step response curves for flowing solids at the exit and the other presents the response curves of the static flowing solids holdup. The model which assumes axial dispersion and exchange between dynamic and two active static zones, most accurately describes the solids flow pattern. A simpler model which presumes exchange between dynamic and one static zone can be used if there is no need for a precise description of the behavior of stagnant particles. The most simple axial dispersion model is not realistic, as it does not explain stagnancy at all, which was experimentally observed for the gas flowing solids fixed bed contactors.

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An approximate analytical solution for the nonlinear inverse axial dispersion model

International Communications in Heat and Mass Transfer ◽

10.1016/0735-1933(90)90027-h ◽

1990 ◽

Vol 17 (6) ◽

pp. 823-830 ◽

Cited By ~ 7

Author(s):

Awad R. Mansour ◽

A.M. Hussein

Keyword(s):

Analytical Solution ◽

Approximate Analytical Solution ◽

Dispersion Model ◽

Axial Dispersion ◽

Axial Dispersion Model

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Gas Hold-Up Evaluation Using the Analytical Solution of the Axial Dispersion Model: Comparison with Static Measurement Results

Chemical Engineering & Technology ◽

10.1002/ceat.200700068 ◽

2007 ◽

Vol 30 (8) ◽

pp. 1020-1027 ◽

Cited By ~ 1

Author(s):

H. Veverková-Majírová ◽

D. Pinelli ◽

F. Magelli ◽

N. Siyakatshana ◽

V. Kudrna ◽

...

Keyword(s):

Analytical Solution ◽

Model Comparison ◽

Dispersion Model ◽

Axial Dispersion ◽

Static Measurement ◽

Measurement Results ◽

Axial Dispersion Model

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Mixing Characteristics for the single and air-water two-phase flows in multichannel-based miniaturized fixed-bed devices

10.22541/au.162637869.92937387/v1 ◽

2021 ◽

Author(s):

Somen Mondal ◽

Subrata Majumder

Keyword(s):

Dispersion Model ◽

Fixed Bed ◽

Flow Distribution ◽

Axial Dispersion ◽

Critical Parameters ◽

Hydrodynamic Characteristics ◽

Two Phase ◽

Axial Dispersion Model ◽

Current Context ◽

Two Phases

Investigation on the miniaturized multichannel-based fixed-bed devices to enhance the heat and mass transfer performance is the key focus in the present study. Residence time distribution (RTD) is one of the most critical parameters to characterize the device’s flow distribution. In the current context, the RTDs of a liquid tracer for the air-water two-phase concurrent flows across the multichannel-based miniaturized fixed-bed devices (consist of 11 number of same dimensional parallel channels) with the variable heights were measured by the conductivity measurements and represented by axial dispersion model (ADM). The stream-flow rates of the two phases varied within the range of 8.33 × 10-8 – 3.83 × 10-7 m3 s-1. The axial dispersion coefficients and the specific energy dissipation values were analyzed. The impacts of pressure loss and the geometry on the hydrodynamic characteristics and mixing properties were well expressed. Based on the experimental data, new correlations were proposed.

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